Hydraulic resaw setwork



D. H. BooKHuLTz ETAL 2,584,837

HYDRAULIC RESAW SETWORK Feb. 5, 1952 '3 Sheets-Sheet 1 Filed May 20. 194'? Feb 5, 1952 D. H. `BOKHULTZ am 2,584,837

HYDRAULIC RESAW SETWORK 3 Sheets-Sheet 2 Filed May 20. 1947 JNVENTORS Donald/aokbu/z and Geofye. Zweifel mig.

Patented Feb. 5, 1952 Donald '1I-I. B'ookhultz and -`George- E. .l Zweifel, @Poi-Hand, Greggassignorsa-toxGeorge. E.1 Zweifel '-Gnmnanyi-.Portland 0.rer;a partnership Application May- 2.0i, 1947;,iseriarNo; '149.1388

..3 laims.

- This invention relates to-hydraulicallyactuated apparatus for feeding-Woodte a saw;N Morepar-y ticularly the invention pertains to y"hydraulically actuated Ysetworks for `accurately Y- positioning large timbers or'cants---with-respect.to a--resaw 5 and 'for-feeding themthereto. v

4/Inthe drawings,

' Figure- 1 is a l-fragmentarysi-de elevation of Aa portion of a saw illustrating Jthe forinandA relative proportionsof the teeth;-

` Figure 2 an-edge=-vlew, partly J in section, y of a saw tooth taken alongthe line-Z--2 ofi-Figure 1;

`Figure 3 isanelevation of the inieed lsidesof the hydraulic setworks Ioftheinvention show-nin relationship to a-band saw--with which `itco-f operates;

' Fig-ure 4 is a Vsideelevationofthe setfroll assembly-viewedfrom the-inside; =and Figure 5 -is a diagrammatic'representation*or the` hydraulic system used= "for Aactuating `:the driven members of the setworks of the invention.

`The resaw; which is-standard equipment in -the average sawmill. sawsy largeatimbersror can-ts coming from-the head rigs into smallentimbers or into boards. In the usualy vlorm,--iti-comprises -a b'andsaw Yof Asubstantial size having in conjunction therevvithdmeans `for positioning: A=the-cantl and vfor urgingsit- Vagainst-the sawA Ito cut a-board of desired dimensions. The combination ofposi-V tioning `and ieedingmeans customarily istermed 30 the setworks Itcomprises" 'two' Igroups of powerdrven-rollers- These-usually are-in va vertical position, although in some resaws-theyy may be ldisposed horizontally. y That group which liesinside the planeof the-saw isca-lledlthe-set 4 roll. nIt` is capable Eofprecise-lateralI adjustment. so that the space between the plane offlthe saw' and the outer periphery of the rollers Y-maybe varied to cut a board ofgiven-thikness AMea--ns also vare present Y for f driving the rollers to urge the timber `'heingprocessed againstfthefsaw.

Disposed oppositethe-fsetfroll and outside=the plane of the saw is another group of rollerswand related members-calledithe1pressvroll. It cooperates with the set roll in feeding a-cant @tothe saw. It also `exerts Vlateral or iclampingrpres sure against the cant to position it rni-'lylagainst thefset roll so that a board ofA uniform thickness will be saWed. To accomplish theseiunctionsut is provided with meanssim-ilartowhose-*presenti 5() in the lset roll for rotating theHiiollerspand-forf adjusting the rassembly 1 Llaterai1yso thatcants of varying cross section-'may be accommodated;

Meansalso --are-provided, however, Lfor-zrnai-n-taii-i-l ing `lateral ypress-ure against ACVtliecant fduingithes A atA; in-Figure 1).

entire periodlin whichlit traversesthe spacey be# tween press-roll and-fsetroll. I

--In thesetwor-ks cooperating with a wband.V Saw ofthe usual resaw assembly there are-thus present three separate `and `independently controlled powerdriven-means i. e., thesmeansffor-driving theerollers of'fthe pressrroll andthe set roll. the meansemployed to `secure the lateral adjustment of theset -roll with 4respect to Athe saw, and 1 the meansfused -to actuate lthevpressfroll .so 'fthat it exerts clampingy pressure against the side` of the cant-fandso -that it is capable efr-lateral ladjustment. IIL-each of these means as-em-ployedf-in therpriorartl devices there are certain inherent deiects-which= tend to vreduce the efciencyqgf the assembly.

There-have been,- ffor example, certain-'inherent deficiencies -ofI electrical, steam and xpneumatic drives-fas applied to the drivingfof lthe-frollersin both/set roll-andpress-roll. The rate at ywhich these-rollers are driven determinesithe speed with whiclrft-he ca-nt is Vfed to the saw. Becauseeof the man-ner -ofconstruction. of the saw, this `rate is of-critical-importance-in determining the'eiliciencyof- 3the-sawing operation and :therquality of-fthe-product obtained. Af sawvcomprisesla pluralityY of teeth 'one a Abody-portion. I'Between the-teeth are cavitiestermedlgullets (indicated These serve rthe function .of carrying away 4the sawdust cut from `the logfby thev cutting lpoints of theteeth. 'The Width `of the cutting-points isY-greaterv-than lthat of the body portion of the -sawby an yamount equal .to

, the difference Vbetween the dimensions designated Brand 0in Figure 2. Hence the cutl or kerf- 1s made -suiicientlyfv -wide to provide clearance Vbetweenfthe body -of the saw andthe solidwood.

This Aallows the saw to movef-reely'zwithin the r kerfjwithout 'binding or friction.

. Ifthe rate at Whichjthe cant is` driven against the saw is too1slowthe:saw will not eutpenough vvoodtor. fill ,the gullets completely and as a consequenceitwill operate at reduced ,efciency It Wil1also consume more `poweixby cutting .the

sawdust `toofine. If, on Athe otherhand, the

cant'is; driven against-the `saw too rapidly. mre

sawdustisiformedthancan be carried away in-the h g-,ulletsieandtproper chambering of the sawdust is snotiobtained. 1 yThe vsurplus :packs andfwedges in the Jkerf-and friction develops. This ,causesv the blade to lheat up, whereupon it loses itstension, waiters,sandfdoesrwt cut in a straight line. ThereA thusis a .certain optimum l speed atzwhich afcant lmust-beadvanced againstthe saws-iff maxi- L? mum cutting efficiency and optimum performance are to be obtained.

Uniform movement of the cant at optimum speed is made diiucult by numerous factors. The cutting speed varies with the length and thickness of the cants. Long cants and cants which are thick are out at different rates than are short cants or cants of relatively small cross section. When a givenv cant is of irregularthickness, as when it is tapered, the speed varies with the thickness of the portion being cut. The density of the wood is also a significant factor, hard woods being cut more slowly than soft woods.

Electric motors, steam engines and pneumatic engines which, as has been indicated above, have comprised the prime movers by meansof whichv the resaw setworks have been driven, have not been susceptible to the preciseN control required to maintain the cuttingnspeed of the resaw at.

uniform, optimum levels., Electric motors operate at either a single speed or at step speeds and hence are not infinitely variable as is necessary to vary the speed to accommodate cants of all types. Furthermore, the speed of an electric motor is variable with the load applied. When the load increases, as whenthe saw meets increased resistance, the motor speed decreases and, conversely, when the load is reduced, the speed of the motor increases correspondingly.

Similarly, the speed of steam and pneumatic engines is variable. Because of fluctuating pressures in the steam or air lines, they operate at varying speeds even at given settings of the controls. Moreover, like electric motors, their olyeratingl speeds are dependent upon the load applied. When the load is increased, the vaporous medium through which power is transmitted is compressed, vwith the resultthat the speed of, the engine is decreased. However, when the load is reducedror released, the compressed medium expands, therebyv accelerating the motion of the engine. Thesefactors impart to their operation an lerratic andl irregular speed which is transmitted to the units of the resaw which they drive. Certain defects also have been inherent in the means heretofore employed for positioning. the set roll with` respect to the blade of the saw. These have comprised mechanical adjustments such as racks and -pinions, screws, and the like. The operation of these devices has been unsatisfactory principally4 because of their lack of precision. Since several parts are involved inthe linkages, the play existing therebetween makes an exact setting impossible, especially after wear has occurred.` Secondly, because of their great weght,they are dicult to operate, particularly when the ways in which the set roll moves are filled with sawdust, as is often the case in the normal operation of the unit. Furthermore, they are incapable of adjustment by remote control and demand the presence of an operator at the set roll when each adjustment is to be made.

Means heretofore employed for securing the lateral' adjustment of the press roll and for securing a constant clamping pressure exerted thereby against the side of the cant have comprised steam and air cylinders and mechanical means such as spring loaded mechanisms.

against the cant. These means, in common with spring loaded mechanisms, therefore result in Steam andv pneumatic cylinders have the disadvantagesl heretofore pointed out of being incapable of pre-v cise control so that uniform pressureis appliedL 4 or otherwise is of irregular cross section. As a. result, the rolls tend to slip or to bind as they act u-pon the cant. This makes the saw vibrate and cut unevenly.

Spring loaded mechanisms have the added disadvantage of being awkward and dicult to adjust, it being necessary to screw them out manually to Vform a large aperture between set roll and press roll when introducinga cant of large cross section therebetween, and to screw them in again when operating upon a smaller cant.

In additionto the deficiencies which are particular to the individual driving mechanisms, i. e. the means driving the rollers, those adjusting the set roll, and thoseadjusting the press roll, the

i apparatus of the prior art has been characterized by lack of integration of these various units. Separate controls'and separate sources of power have been employed for each. It has not been possible to control the apparatus entirely from a position remote from the resaw, as from a position adjacent a live roll track by means of which thercants are fed into the machine. The apparatus has been hazardous to operate, both to operating personnel and to the lumber processed, because of the danger ofpersonnel being drawn between the rollers, and because of damage which may be done to the lumber by faulty operation of the saw and byre. 'I'here has been the further hazard, that because of the difficulty of4 controlling the Vmovement of the cant between the rolls, it frequently is impossible to stop its motion with sufficient speed to prevent the saw from being damaged or pushed off the driving wheels when it strikes a rock or metal obj ect buried in the cant.

It is, therefore, the general object of the present invention to provide la resaw setworks which comprisesan integrated, efficient unit which is easy to operate and which is subject to precise control. v n

It is a further object to provide a setworksl for a resaw, the controls of which may be grouped together at some convenient location which may be remote from the saw.

A further object is to provide apparatus for feeding cants against a sawvwhlch apparatus is relatively simple and has a minimum of operating parts. u A

A furtherobject is to provide a setworks for a resaw which may be operated at a minimum of hazard to personnel and to the material processed. A

A further object is to provide a resaw setworks the rollers of which may be rotated at a controlled and. steplessly variable speed calculated to urge a cant positioned therebetween against the saw at an optimum cutting speed throughout the entire cutting operation. y

A further object is to provide means in a resaw setworks for securing the precise lateral adjustment of set roll and press roll Iwith respect to the saw.

A further object is to provide in a resaw setworks means for securing a uniform and optimum pressure of the press roll against the side of ,the cant. i

vIt is the essence of the present invention that the foregoing and other objects may be accomplished by the application of suitable hydraulically driven mechanisms to the actuation of the rollers of Vthe set roll and press roll, to the lateral adjustmentof the Aset roll and pressfroll I. with respect to the saw, and to the application, of, clamping pressure bythe press rollagainstjthe cant. The -manner in whichlaccomplished-will f be-1'a.ppa1ent-` from- .-aconsideration of the =followingspecilicationand-claims yconsideredtogetherwith theidrawings. i l I -In FigurestB-and 4, a cant Il! is Arepresented in process 'of 'being operated vuponby Lthetband s sawV Il. 'Ihe` saw rides-'cna pair-of wheels,the-upper wheel 1| 2 being mounted onir a` shaft-v orfarbor Ill 5 journalled inthe bearing-lwhich issupported by the member vI'i. 'Bhe-lower 'wheel-12); which drives the saw, is `similarly mounted'fitsarbor 2| being journalled linto the bearingvfsupported by the yoke 25. Y

The setworks which ffeeds thesaw, comprises theset roll, thepress'roll 'and-related members: mounted upon a base 2S or supporting r`structure on theinfeed side of the saw,l the-set roll-.being inside and the press roll rbeingrouts-idei-the plane thereof. A Theset roll The set roll assembly. comprises aplurality oi rollers 363, 3G, 3i) preferably three in number, `rotatably mounted in substantial .alignmentand positioned with their axes,substantiallycparallel to the cutting portionlof the saw. The rollers preferably have av roughsurface, e. g. a .uted surface, so as to engage thecantfirmly. The ends of the rollers are providedrwith shafts, the lower shafts 3i, 3l, 3| ybeing journalled into4 the bottom of a framework or. housing .-32 andthe upper shafts 35, 35, 35`ibeing journalled-intof the opposite side of the same housing.

The rollers of the set roll assembly are driven by the hydraulic motor 36, which is mounted on the housing or husk 32. The motor is of the variable speed, rotary typeand is 4supplied with hydraulic iiuid under pressure in a manner to be described hereinafter. It is attached through a suitable gear reduction train, 4indicated .generally at 38, 38, 38. to. the uppershafts ofthe rollers. Y

It will be apparent that as a consequence of the fact that many of the cants processed by. the resaw are of relatively small cross section and contact only the. lower portion of the rollers, the latter will be Worn unevenly with use over a period of time, the greatest wear occurring on the lower portions. As a result, the space between the periphery of the saw. and the rollers, which determinesthe thickness of the out, will vary and will affect the dimensions ofthe lumber sawed. To compensate forthis, means are provided for tilting the set roll assembly periodically so that the lower portions of the rollers are shifted toward the saw by an amount suflicient tocorrect for the amount of wear. 'Thisisjaccomplished by pivotally mounting theY entire 'assembly on a supporting member 4i] throughthe opposi-tely disposed trunnion b'earingsl, 4l.

Y Theset roll assembly'isv locked in the adjusted position by means of the bolts '42, '42 with nuts 45, 45.' 'The bolts penetrate the housing- 32 rand extend through slots, one ofY which is indicated at 46, 'in the support member 4B. Thus, Athefdesired adjustment of the set-'roll may be secured and maintained. byv loosening the' nuts-on thebolts,y tilting the set roll `to the extentfdesired,V and then tightening the nuts. vIt will be appar# ent-to one skilled in the art, however, that falternate means may be employed to secure such ad` justment, 'as' stops-affixed. kto the lbottom .of the support member 40 and connectedthrough. anv adiustablescrew totheghousing 32, 4or otherwise To make possible the lateral .adjustment of. the set vroll assemblyY with respectioxthe lcutting:

7 one of which is indicated at 66.

portion -of `thesaw,-the^entire assembly iisllsliclably mountedon`-the=slides-4l, -41- which preferably-larefformed J'integrally-with the vsupport 'member d and which are adapted to move on meansofA areciprocable hydraul-icram the cylinder 5l' ofwhichis attachedthrough-the bracket 52-=to the` slidably- -mounted `support lmemberI 43,'

andthe piston `53 of whichis-connected through thetpiston--rod' to a-br-acket on. the -base of the y-setworks orto an extension-ofone `of-the guide members 5B. Control of the velocity and direction fof motion of the .ram is had through the valve `55 and control lever 56fwhich operate' to .route iiuid to oneside-or the other'of-the piston 53. The valve -preferably is. attached to the cylinder 5| land is supplied withiluidunder4 pressure. from a hydraulic pump as more-:fully is described below. Suitable adjustmentotthe Valve thus causes displacement of `thepiston 'and movement of the setroils to anew andpredeV` termined position.

Press roll and operatively connected through a gear .train to the hydraulic motor 6 l. This motorcooperates withthe set roll motor. St: and like .it is ofthe variable speed, rotary type.v It -is .suppliedvwith hydraulic fluid, from: the l same pump v .that supplies fluid to the set roll '.motor. ..Set roll and press roll thus are driven independentlyof each other mechanically, but a-re tiedtogether hydraulically. Their speed and direction or. rotation are controlled by means of the throttle Vvalve -63 and the reversing valve .6d which `preferably' are ailixed to the. frame of the sawat some point-convenient to the operator. These two valves vare so constructed that the throttle valve :controls the volume of hydraulic Afluid, supplied to the motors 3G andil in a unit time, and hence their speed, while the reversing valve controls the di rection of iiow of the luidthrough-the motors, and hence their direction of rotation.

.Tilting of the press roll .tocompensatelfor wear on the lower portion of. the rollers is ace complished in the samemanner asin the .case of the set roll. The housing containing the rolls is mounted on a supporting member G5 through oppcsitely disposed trunion bearings After tilting, the assembly is locked in. position by means of bol-ts extending through the housing andithrough the supporting member G5. These bolt's are disposed on opposite sides of the assembly, Lone of them 67 with nut S8 extending through the slot. in the supporting member 65.

. The press roll, like the set roll, may-befadjusted laterally with respect to the saw, the adjustment being made in this instance to accommodatecants of varying sizes betweenv the rollers. Thus, the. press roll is mountedonslides which preferably are formed integrally with' the support member .65 and which are adapted tomove on guides, oneof which is indicated at Til, attached to or formed integrally with the base of the-setworks. t is adjusted laterally with respect to the saw as required by the` size vfof the .cant by'y means ofa reciprocable hydraulicram, the -cylinder .7| fof which4 4is s attached to the press roll assembly, asxby being@ attached tol an fextension'f on the guide 10. Within the cylinder slides the piston 12 which is attached through the piston rod 'I3 to the bracket 14 on the support member 65.

The press roll ram is adapted to exert sustained clamping pressure on the cant as it passes through the setworks, the amount of presure being variable as required for optimum operation of the unit. It is controlled by means of the four-way valve 80, which may be positioned adjacent the controls for the hydraulic motors for the press roll and set roll and the control for the set roll ram. This valve is adapted to direct the fluid flow to one side or the other of the piston 12, thereby effecting its reciprocation. It is supplied with fluid under pressure from a suitable hydraulic pump as is hereinafter described.

Also present on the setworks assembly is the roller 85 rotatably attached through bearings B6, 86 to the brackets 81, 8l. This roller serves the function of co-operating with other rollers in a live roll assembly to feed the cant into the setworks.

The hydraulic system Details of the hydraulic system controlling the operation of the various hydraulic units of the setworks assembly are illustrated in Figure 5. A large, constant speed electric motor 88 drives three separate hydraulic pumps indicated respectively at 90, 9| and 92. These may all be driven from the shaft of the electric motor and, therefore, operate at the saine speed. The entire unit comprising the electric motor and the three pumps is mounted on the tank or reservoir 93 in which hydraulic fluid is stored and to which it is returned through the lines designated throughout the figure by the symbol T.

The hydraulic system through which fluid under pressure is supplied to the hydraulic motors 36 and 6| which drives, respectively, the set roll and the press roll, comprises the variable displacement pump 90, the throttle Valve 63, the reversing valve 64, preferably an equalizing valve 9G, and interconnecting flow lines or conduits. When the motor 88 is running, it turns the variable displacement pump 90 at constant speed. The amount of uid fed by the pump to the hydraulic circuit is determined by the setting of the throttle valve 63. When this valve is in neutral or idling position, the pump displaces and delivers substantially no fluid. The hydraulic motors 36 and 6| therefore remain idle. However, as the throttle valve is advanced, the pump displaces and delivers through line 91 a steplessly variable flow of fluid. This passes through the throttle valve; through line 98. to the reversing valve, which determines the direction of flow through the rest of the circuit; through the lines 95 to the equalizing valve 96, which equalizes the ow between the two motors; through one of the lines 99, 69 (as determined by the setting of the reversing valve) to the motor 3S; and through one of the lines |00, |06 to the motor 6| which is in parallel with motor 36. Fluid exhausted from the motors is returned to the tank through the lines IUI and |02. The two motors thus are tied together hydraulically and are governed by adjustment of the same controls, although they operate as independent mechanical units.

The hydraulic circuit by means of which the set roll positioning ram is operated comprises the constant displacement pump 9|, the relief valve |06 and the four-way valve 55 attached to the cylinder These units are interconnected by the infeed line |01. rluid exhausted from the cylinder is returned to the tank through line |08. When valve 55 is in neutral position, there is substantially no flow of fluid through the circuit and the cylinder remains stationary. However, upon movement of the control lever the flow is initiated and the ram is extended or retracted. This moves the set roll together with the attached cylinder and valve to a new position as desired.

The relief valve is included in the circuit to relieve the pressure when the motion of the set roll is impeded. It therefore serves a safety function.

The hydraulic circuit for the press roll assembly comprises the adjustable pressure, constant displacement hydraulic pump 92 supplying fluid through the line ||0 to the four-way valve 8i) which controls the direction and velocity of motion of the press roll positioning ram. The pump is provided with the presure adjustment which enables application of variable and sustained presure through the ram to the cant upon which the press roll operates. As in the case of the set roll positioning cylinder, there is no flow of hydraulic fluid through the circuit when the control valve B0 is in neutral position. However, upon suitable movement of the control lever, the flow of fluid is initiated through lines ||2 so that the ram may be actuated to adjust the position of the press roll and to maintain pressure on the cant. Fluid exhausted from the cylinder during operation of the ram is returned to the tank through line H3.

Operation In operation of the resaw, a cant is fed between the rollers of the set roll and press roll. These are driven by means of the hydraulic motors 36 and 6| at a speed calculated to advance the cant against the saw at an optimum rate at which the saw operates at maximum efficiency, i. e. at which the gullets between the saw teeth are filled to capacity with sawdust without surplus sawdust wedging in the kerf. Since the speed of the motors is a function only of the amount of hydraulic fluid pumped therethrough and is independent of the load placed upon them, they may be operated at a constant, predetermined speed which is the optimum for a cant of given dimensions and type. However, when it is necessary to vary the speed of thev motors. as when cants of varying thickness or density are being processed, the speed of the motors is steplessly and instantly variable to protect the saw from damage or to maintain its cutting efllciency.

, Furthermore, substantially instantaneous and cushioned stopping of the motion of the cant may be obtained at any point during the cut, or if desirable or necessary the direction of motion of the cant may be completely reversed.

The set roll and press roll also may be operated with comparative safety to the personnel of the mill. Since the hydraulic motors driving each are mechanically independent of each other but are connected in parallel hydraulically, one of the rollers may be stopped manually, whereupon the quantity of hydraulic fluid passing through the other motor will be doubled and the speed of the rolls which it drives likewise is doubled. It is only when a cant is introduced between the rollers that power is applied equally to each of the motors and they divide the load equally between them. As a consequence, it is a virtual impossibility for a person to become v easyto .make by a simple adjustment 'f the 'controll'ever, which moves the piston of the .ram to a' desired extent ineither direction and "thereby positions the set roll. The positioning apparatus is compactand simple. Itis not subject 'to inter'ference by the presence v'i'.ffsawdust as "is a VI'In'echanical apparatus, nor :are there mechanical linkages which .wear andthusine'gative the .piieci'sion of -the apparatus.

Lateral adjustment of the press roll with respect to the saw is secured by adjustment of the positioning cylinder 'il by suitable adjustment of the control lever. This enables accommodating cants of varying widths between the rollers of the set roll and press roll. Since the positioning cylinder is also adapted to exert a given pressure against the framework of the press roll, the latter exerts a clamping action against the cant and holds it firmly in place. The clamping pressure thus exerted is uniform and is not variable as is the case with steam cylinders, pneumatic cylinders or spring loaded mechanisms. As a result there is no binding or slippage of the cant and the saw makes a true cut therethrough. Since the pressure applied to the press roll is constant, the press roll follows the irregularities when cants of irregular dimension, as tapered cants, are introduced into the set works, exerting a constant pressure throughout the peration.

In addition to the specific advantages attendant upon the application of hydraulic actuation to the motors driving the set roll and the press roll, to the set roll positioning cylinder and to the press roll positioning cylinder, there are general advantages attending the overall application of hydraulic actuation to these various mechanisms. It provides for the first time integrated means for driving these three units from a common power source. It is also possible for the first time to operate the setworks from a remote position. This is desirable since it enables a single operator stationed midway down a live roll assembly feeding cants into the resaw to have available to him but three control levers closely grouped together, each of which operates one unit of the setworks.

The driving mechanism is simplified to a minimum of mechanical parts and linkages. permits operation of the resaw with the greatest degree of precision, economy and freedom from vibration.

Hazards attendant upon operation of the assembly also are largely minimized. The danger of operating personnel becoming fouled in the rollers when they are freely revolving is negatived by the fact that either set of rollers may be stopped manually by reason of the diversion of hydraulic fluid to the other set of rollers when resistance is met by the first set. Furthermore, the fire hazard to the mill is greatly reduced because of the absence of steam power plants.

Having now described our invention in preferred embodiments, what we claim as new and desire to protect by Letters Patent is:

1. In combination with a resaw, setworks comprising a base, a set roll frame slidably mounted on said base, a plurality of rollers rotatably mounted in said set roll frame, a first fluid op- "erated rotary motor operably vconnected to said rollers in said set roll frame, v'valve means for controlling said first fluid operated rotary motor, a first hydraulic cylinder, a piston therein Aoperatively connected to said set roll frame, valve means for directing 'the' flow offiuid to the respective sides of said piston in said first hydraulic cylinder, whereby to secure the reciprocation thereof and the lateral adjustment of said set roll frame, a press roll frame slidably mounted on said base, a plurality of rollers rotatably mounted in said'press roll Vframe, a second fluid operated rotary motor operably Vconnected to 'said rollers in said' press roll frame, valve means for controlling said second iiuid Aoperated -rot'ary motor, a second hydraulic cylinder, a piston therein operatively connected 'to said press roll frame, valve means for directing the fiow of fluid to the respective sides of said piston in said second hydraulic cylinder whereby to secure the reciprocation thereof and the lateral adjustment of said press roll frame and the exertion of clamping pressure by the rollers therein, a variable displacement rotary pump, conduit means interconnecting the same and said first and said second rotary hydraulic motors and the valve means therefor, a constant displacement pump, conduit means interconnecting the same and said first hydraulic cylinder and the valve means therefor, a constant displacement variable pressure pump, and conduit means interconnecting the same and said second hydraulic cylinder and the valve means therefor.

2. In a resaw, a set roll assembly slidably mounted on the frame of the resaw, a first hydraulic cylinder, a piston therein operably connected to the set roll assembly, valve means for directing the fiow of fluid to the respective sides of the piston in the first hydraulic cylinder whereby to secure the reciprocation thereof and the lateral adjustment of the set roll assembly, a press roll assembly slidably mounted on the frame of the resaw, a second hydraulic cylinder, a piston therein operably connected to the press roll assembly, second valve means for directing the flow of fluid to the respective sides of the piston in the second hydraulic cylinder whereby to secure the reciprocation thereof and the lateral adjustment of the press roll assembly and the exertion of clamping pressure by the rolls therein, a constant displacement pump, conduit means interconnecting the same and the first valve means and the rst hydraulic cylinder, a constant displacement variable pressure pump, and conduit means interconnecting the same and the second Valve means and the second hydraulic cylinder.

3. Resaw setwork comprising a base, a set roll frame slidably mounted on said base, a plurality of rollers rotatably mounted in said set roll frame, a first fluid operated rotary motor operably connected to said rollers in said set roll frame, valve means for controlling said first fluid operated rotary motor, an hydraulic motor connected to said set roll frame for securing the lateral adjustment of the same, valve means for directing the fiow of fluid to the set roll adjusting motor, a press roll frame slidably mounted on said base, a plurality of rollers rotatably mounted in said press roll frame, a second fluid operated rotary motor operably connected to said rollers in said press roll frame, valve means for controlling said second fluid operated rotary motor, an hydraulic cylinder, a piston therein operatively connected to said press roll frame, valve means for directing the ow of fluid to the respective sides of said piston in said hydraulic cylinder whereby to secure the reciprocation thereof and the lateral adjustment of said press roll frame and the exertion of clamping pressure by the rollers therein, a variable displacement rotary pump, conduit means interconnecting the same and said rst and said second rotary hydraulic motors and the valve means therefor, an hydraulic pump, conduit means interconnecting the same and the set roll adjusting motor and the valve means therefor, a constant displacement variable pressure pump, and conduit means interconnecting the same and said second hydraulic cylinder and the valve means therefor.

DONALD H. BOOKHULTZ.

GEORGE E. ZWEIFEL.

l2 REFERENCES CITED The following references are of record in the le of this patent:

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